A cost-practical cell-recycling process for xylonic acid bioproduction from acidic lignocellulosic hydrolysate with whole-cell catalysis of Gluconobacter oxydans

Xylonic acid (XA), as a bio-based platform chemical, is of considerable interest for xylose bioconversion. The whole-cell catalysis of Gluconobacter oxydans presents a promising application potential, while the hard works of cell culture still severely hinder XA business from the crude toxics-containing lignocellulosic hydrolysate. Hence, the bacterial cells should be recycled to reduce commercial production cost. The implementation of diatomite detoxification not only absorbs most of the degraded inhibitors in hydrolysate, but also confines the sugar contents loss with 10% and allows the bacterial cells to maintain 90% bioconversion performance during cellrecycling operation. Additionally, a scale-up of XA bioproduction was achieved in a sealed oxygen supply fermenter. Finally, 210 g XA was produced from 1000 g corncob originated hydrolysate within 24 h of whole-cell catalysis. Diatomite treatment provides an efficient and cost-practical approach for the commercial bioproduction of biochemicals like XA from lignocellulosic biomass.

Automated summary

The study demonstrates that diatomite detoxification can effectively achieve commercial production of bio-based chemicals like xylonic acid, reducing costs by recycling bacterial cells. Additionally, a scale-up production of xylonic acid was achieved in a sealed oxygen supply fermenter. Overall, diatomite treatment provides an efficient and practical approach for the production of biochemicals.